1. Field of the Invention
The present invention relates to an apparatus and method for a digital video broadcasting system. More particularly, the present invention relates to a digital video broadcasting system, digital video broadcasting terminal, and method for providing information about downloadable files using an Electronic Service Guide (ESG) in a file download service.
2. Description of the Related Art
Generally, in a digital broadcasting system, a broadcasting signal, which has been conventionally transmitted in an analog manner, is transmitted in a digital manner. A broadcasting signal transmitted in a digital manner provides superior quality and provides various services for both video and audio. Digital broadcasting is classified as Digital Video Broadcasting (DVB), Digital Audio Broadcasting (DAB), Digital Multimedia Broadcasting (DMB), MediaFLO, and the like. DVB is a European digital broadcasting standard and can be classified into various forms according to its nature, such as DVB-Terrestrial (DVB-T), DVB-Satellite (DVB-S), and DVB-Handheld (DVB-H). DVB-T is a standard for terrestrial digital broadcasting, DVB-S is a standard for satellite digital broadcasting, and DVB-H is a standard for portable mobile digital broadcasting.
DVB-H is a technology standard established for the transmission of digital signals to handheld devices such as mobile terminals and the like. DVB-H provides excellent reception of terrestrial digital broadcasting to handheld devices (i.e. mobile terminals). Moreover, it can be used to implement digital mobile multimedia broadcasting to provide high-quality video and audio content to users anytime and anywhere, for example while driving or walking.
Unlike other digital broadcasting standards, DVB-H transmits important information required for a broadcasting service through Electronic Service Guide (ESG) data. DVB-H uses a File Delivery over Unidirectional Transport (FLUTE) protocol as a Content Delivery Protocol (CDP). The FLUTE protocol allows transmission of files such as text, audio, video and image files. As part of its standard, DVB-H uses the FLUTE protocol to download files required for ESG configuration and ESG update.
DVB-H provides video broadcasting and audio broadcasting as fundamental broadcasting services. In addition, DVB-H provides a data broadcasting service. In other words, three types of services, i.e., video service, audio service and data service, can be provided by the DVB-H standard. Information about each of the three services is transmitted through ESG information. A terminal, for example a handheld device, receiving a DVB-H broadcasting signal, analyzes ESG information included in the broadcasting signal in order to recognize the type of service transmitted through the broadcasting signal and service related information. The ESG information includes Extensible Markup Language (XML) data, and the format of ESG XML information is defined using an XML scheme in the standard.
DVB-H broadcasting information is transmitted as ESG fragment information. An ESG fragment can be classified into various types according to the information included in the ESG fragment. ESG data defined in the DVB-H service includes 7 fragments, i.e., a service bundle fragment, a purchase fragment, a purchase channel fragment, a service fragment, a schedule event fragment, a content fragment, and an acquisition fragment. The terminal collects these fragments together in order to recognize all of the information contained in the DVB-H broadcasting signal.
A DVB-H broadcasting service includes a data broadcasting service. A data broadcasting service is a file download service that involves downloading a particular data file transmitted through a broadcasting signal. In the file download service, file data required for a service, such as an HTML page, Audio/Video (AV) files, and ring tones, in addition to a streaming service, is transmitted using the FLUTE protocol. In order to acquire file data used for a particular period of time, a FLUTE session is initiated using Session Description Protocol (SDP) information of the ESG data and the desired file data is transmitted. In the file download service, information required for the file download service is transmitted using the service fragment, the schedule event fragment, the content fragment, and the acquisition fragment of the ESG data.
FIGS. 4A and 4B illustrate an ESG for a DVB-H file download service. Uniform Resource Identifier (URI) information for each transmission file is transmitted through a schedule event fragment. It can be seen from FIGS. 4A and 4B that a download service for three ring tone MP3 files, i.e., a Ring Tone 1, a Ring Tone 2, and a Ring Tone 100, is provided. More specifically, it can be seen from FIGS. 4A and 4B that URI information for each MP3 file is transmitted through a content location element of the schedule event fragment. As can be seen from FIGS. 4A and 4B, information required to provide the download service for the three MP3 files is transmitted through the content fragment, the service fragment, the schedule event fragment, and the acquisition fragment. FIG. 5 illustrates the syntax of a general ESG schedule event fragment. Referring to FIG. 5, a content location element 500 of the schedule event fragment has information about the type of any URI and can indicate URI information of a single service file.
As such, when the current DVB-H system provides file information for a download service using an ESG, it can provide information about a download service for a single file as illustrated in FIGS. 4A and 4B. However, when several individual files are grouped together for download in the file download service, there is no way to provide information about each of the several files included in the grouped file. As a result, when a set of several files is provided in a file download service, information about each of the several files included in the set may not be provided.
For example, when a service provider offers 10 ring tone MP3 files, grouped together as a single file, to a user for purchase, the user may desire to evaluate information about each of the 10 ring tone MP3 files, i.e., a file list, before paying for and downloading the 10 ring tone MP3 files. However, according to the current DVB-H Convergence of Broadcast and Mobile Services (CBMS) ESG standard, when a terminal is provided with several files grouped as a single file, there is no way to provide information about each of the individual files of the grouped file, thus resulting in a failure to provide sufficient information to the user.